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Guess the Correlation

April 14, 2021 By editor

People find it difficult to intuitively gauge the level of correlation between variables.

Guess the Correlation is an 80s-style video game that lets you flex you estimation muscles.

Just be aware that it doesn’t seem to present negative correlations, so you’ll have to intuit those elsewhere.

Filed Under: Data analysis, Data science Tagged With: correlation, game, statistics

Why it’s hard to find good data science courses

April 10, 2021 By editor

Why is it so hard to find effective data science courses? For instance, courses that cover the practical work involved in going from problem to solution?

This is a question I was asked last week. To answer it, we can employ basic mathematics.

Draw a Venn diagram. Include the following sets.

  • people who are good at statistics
  • people who are good at coding
  • people who have good social skills
  • people who have good teaching skills
  • people who have good technical writing skills
  • people who couldn’t be making a shitload more money doing something else

Count the number of people in the intersection of those sets. That’s why.

Filed Under: Data science Tagged With: training

Mathematics & Statistics Awareness Month

April 9, 2021 By editor

April is Mathematics & Statistics Awareness Month.

Let’s celebrate it by making sure we embrace statistics in our data science projects. It’s not just about Python, folks!

Filed Under: Data science Tagged With: statistics

Sharks are definitely scarier than mosquitos

March 24, 2021 By editor

Bill Gates retweeted a World Health Organization infographic showing that mosquitos kill vastly more people than sharks every year—on the order of 100,000 times more.

In his tweet Bill captioned the infographic with, "Why I would rather encounter a shark in the wild rather than a mosquito." Presumably he’s referring to man-eating sharks.

This was an informal comment designed to highlight the misery caused by malaria—a cause that is at the centre of Bill’s philanthropy. Clearly it wasn’t supposed to be a serious risk assessment.

But it illustrates how confusing conditional probabilities are, and how easy it is to make invalid statistic inferences.

The data in the infographic refer to the probability that, given you are dead, you were killed by a shark or a mosquito. Chances are that it was a mosquito—not a shark. That seems intuitive.

Technically, we can denote this as

$P(shark|death) << P(mosquito|death)$

I’m not convinced by Bill’s implication that it’s better to encounter a shark than a mosquito. I grew up after "Jaws" was released. Intuitively, surely sharks are much more dangerous, right?

The risk posed by meeting either of these creatures is the probability of being killed given you met them. If we encountered man-eating sharks as often as we encounter mosquitos we’d be getting munched on constantly.

Sharks are definitely scarier. We can represent this more formally as

$P(death|shark) >> P(death|mosquito)$

It’s important that we distinguish between $P(mosquito|death)$ and $P(death|mosquito)$ when drawing inferences.

Fortunately man-eating sharks live in the ocean and I don’t. Given that, I’m willing to sign up for more killer sharks and less mosquitos.

Filed Under: Data science, General Tagged With: conditional probability], statistics

What the hell is “data science” anyway?!

February 19, 2021 By editor

Too much time has been squandered on trying to define data science, AI, machine learning, data analysts, data thingymajig, etc.

Who cares? I’m happy to return to “statistics” and “programming”.

We should follow the lead of United States Supreme Court Justice Potter Stewart.

I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description [“hard-core pornography”], and perhaps I could never succeed in intelligibly doing so. But I know it when I see it…

Filed Under: Data science Tagged With: definitions

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Recent posts

  • Guess the Correlation
  • Why it’s hard to find good data science courses
  • Mathematics & Statistics Awareness Month
  • Sharks are definitely scarier than mosquitos
  • What the hell is “data science” anyway?!

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